There's really a lot to tell about Internet Explorer 9, so I don't really know where to start. First of all, you can download a test version, called the IE9 Platform Preview. This preview will be updated every eight weeks, and customer feedback will be taken into account - presumably much like the Windows 7 development phase.
That's not the only thing that IE9 will hand off to hardware - text, graphics, and SVG rendering will be hardware accelerated as well, providing, according to Microsoft at least, better performance than other browsers.
A hot iron is obviously standards compliance, and it appears that Microsoft has finally learnt its lesson with this one. The post on the IEBlog announcing the IE9 MIX10 details is full of holding hands and flowers and free hugs, and the current Platform Preview build scores 55/100 on the ACID3 test. Microsoft is asking for feedback on this stuff.
"The main technologies to call out here broadly are HTML5, CSS3, DOM, and SVG," Microsoft writes, "The IE9 test drive site has more specifics and samples. At this time, we're looking for developer feedback on our implementation of HTML5's parsing rules, Selection APIs, XHTML support, and inline SVG. Within CSS3, we're looking for developer feedback on IE9's support for Selectors, Namespaces, Colors, Values, Backgrounds and Borders, and Fonts. Within DOM, we're looking for developer feedback on IE9's support for Core, Events, Style, and Range."
At the Platform Preview site, there's a whole bunch of browsers tests to perform, and, of course, you can download the latest IE9 build - new territory for Microsoft. This is what competition can do, and it's good. Especially the hardware acceleration sounds incredibly interesting.